12 research outputs found
Vers une nouvelle conception du pre-breeding ? Quel partenariat public-privé ?
AprÚs avoir défini le pré-breeding, son rÎle et son positionnement dans les schémas de sélection,une analyse de l'organisation du partenariat public-privé est présentée en s'appuyant sur des exemples.L'impact des marqueurs moléculaires sur l'efficience du transfert de caractÚres innovants dans despools élites est également souligné par des exemples. Des éléments d'évolution du contexte de mise enoeuvre du pré-breeding sont déclinés. Des interrogations sont formulées quant à l'évolution de larépartition des missions entre la recherche publique et la recherche/sélection privée, les moyensd'assurer le transfert, la valorisation des connaissances produites par la recherche publique, et le rÎlede celle-ci concernant les espÚces mineures, voire orphelines de recherche
Vers une nouvelle conception du pre-breeding ? Quel partenariat public-privé ?
National audienceAprÚs avoir défini le pré-breeding, son rÎle et son positionnement dans les schémas de sélection,une analyse de l'organisation du partenariat public-privé est présentée en s'appuyant sur des exemples.L'impact des marqueurs moléculaires sur l'efficience du transfert de caractÚres innovants dans despools élites est également souligné par des exemples. Des éléments d'évolution du contexte de mise enoeuvre du pré-breeding sont déclinés. Des interrogations sont formulées quant à l'évolution de larépartition des missions entre la recherche publique et la recherche/sélection privée, les moyensd'assurer le transfert, la valorisation des connaissances produites par la recherche publique, et le rÎlede celle-ci concernant les espÚces mineures, voire orphelines de recherche
High-Affinity Manganese Uptake by the Metal Transporter NRAMP1 Is Essential for Arabidopsis Growth in Low Manganese Conditions[C][W]
This study shows that, in order to acquire manganese when concentrations in the soil are limited, Arabidopsis relies on a root high-affinity manganese uptake system catalyzed by the metal transporter NRAMP1. The finding that overexpression of NRAMP1 produces large plants with increased manganese content paves the way for the biotechnological engineering of plants with improved biomass production
The NRAMP6 metal transporter contributes to cadmium toxicity
International audienceNatural Resistance Associated Macrophage Protein (NRAMP) homologues are evolutionarily conserved divalent metal transporters. In Arabidopsis, AtNRAMP3 and AtNRAMP4 play a key role in iron nutrition of the germinating plantlet by remobilizing vacuolar Fe stores. Here we describe the molecular and physiological characterization of AtNRAMP6. AtNRAMP6 is predominantly expressed in the dry seed embryo and to a lesser extent in aerial parts. Its promoter activity is found diffusely distributed in cotyledons and hypocotyls as well as in the vascular tissue region of leaf and flower. We show that AtNRAMP6 transcript coexists with a partially spliced isoform in all tested shoot cell types. When expressed in yeast, AtNRAMP6, but not its misspliced derivative, increased sensitivity to cadmium without affecting Cd content in the cell. Likewise, Arabidopsis transgenic plants overexpressing AtNRAMP6 were hypersensitive to Cd although plant Cd content remained unchanged. Consistently, a null allele of AtNRAMP6, named nramp6-1, was more tolerant to Cd toxicity, a phenotype that was reverted by expressing AtNRAMP6 in the mutant background. We used an AtNRAMP6::HA fusion, shown to be functional in yeast, to demonstrate through immunoblot analysis of membrane fractions and immunofluorescence localization that, in yeast cells, AtNRAMP6 is targeted to a vesicular-shaped endomembrane compartment distinct from the vacuole or mitochondria. We therefore propose that AtNRAMP6 functions as an intracellular metal transporter, whose presence, when modified, is likely to affect distribution/availability of Cd within the cell
Diversification : de nouveaux traits, de nouvelles espÚces pour de nouveaux services et une stabilité des rendements en conditions de faibles intrants
National audienc
Projets IVD INRA-AgriObtentions variétales pour les légumineuses à graines
Prod 2018-220l BAP GEAPSI INRANational audienc
Expertise scientifique collective : variétés tolérantes aux herbicides
Lâexpertise Scientifique Collective (ESCo) menĂ©e en 2010â2011 par lâINRA et le CNRS sur les variĂ©tĂ©s vĂ©gĂ©tales tolĂ©rantes aux herbicides (VTH) a Ă©tĂ© coâcommanditĂ©e par les MinistĂšres de lâAgriculture, de lâAgroalimentaire et de la ForĂȘt (MAAF) et de lâEcologie, du DĂ©veloppement durable et de l'Energie (MEDDE) suite aux premiĂšres propositions, par le ComitĂ© Technique Permanent de la SĂ©lection des plantes cultivĂ©es (CTPS), dâinscriptions sur le catalogue officiel français de variĂ©tĂ©s de tournesol et de colza prĂ©sentant une tolĂ©rance Ă la famille herbicide des imidazolinones. L'ESCo porte sur le caractĂšre agronomique de tolĂ©rance Ă un herbicide (TH), auquel l'espĂšce est normalement sensible, quelle que soit la technique d'amĂ©lioration gĂ©nĂ©tique employĂ©e pour en doter une variĂ©tĂ©. Cette ESCo vise Ă Ă©valuer « lâimpact en terme dâagronomie, de santĂ© des plantes et dâenvironnement, dâĂ©conomie et de perception par la sociĂ©tĂ© de la diffusion de variĂ©tĂ©s de plantes cultivĂ©es prĂ©sentant le trait gĂ©nĂ©tique de la tolĂ©rance Ă un herbicide » AprĂšs une adoption rapide par les agriculteurs dans le contexte nord amĂ©ricain, la solution technique apportĂ©e par les VTH gagne progressivement la France, notamment pour le tournesol (150 000 ha semĂ©s en VTH en 2015, soit 20 % de la sole nationale de tournesol). Dans le cas du colza, en raison de lâarrivĂ©e plus tardive de VTH sur le marchĂ©, seuls 9000 ha sur les 1,5 Mha Ă©taient semĂ©s en VTH en 2013, et environ 20 000 ha en 20141. NĂ©anmoins, le potentiel de croissance est supĂ©rieur Ă celui du tournesol prĂ©sageant dâune adoption plus large (intentions de semis de 20152 estimĂ©s Ă 40 000 ha). La restitution des conclusions de cette ESCo a conduit Ă lâĂ©laboration et Ă la mise en oeuvre dâun plan dâaction, suivi par le MAAF, visant Ă encadrer la diffusion et lâutilisation de ces variĂ©tĂ©s dans le but de se prĂ©munir des risques associĂ©s Ă lâutilisation systĂ©matique de la mĂȘme famille herbicide sur la mĂȘme parcelle Ă lâĂ©chelle de la rotation. En effet, si ces VTH sont susceptibles de constituer initialement une rĂ©ponse technique Ă des difficultĂ©s de dĂ©sherbage, et si leur culture est prĂ©sentĂ©e simplement comme permettant une rĂ©duction des quantitĂ©s d'herbicides utilisĂ©es, leur mise en culture rĂ©pĂ©tĂ©e, ne prenant pas en compte l'Ă©volution concomitante des flores adventices, peut rapidement rendre inefficace cette stratĂ©gie et faire ressurgir ces difficultĂ©s, Ă©ventuellement plus complexes encore Ă gĂ©rer. Le plan dâaction vise donc la mise en oeuvre de mesures de suivi de lâapparition Ă©ventuelle des rĂ©sistances chez les adventices et la diffusion de prĂ©conisations et dâun conseil agricole en mesure dâĂ©clairer au mieux le choix et les pratiques des agriculteurs dans le cadre dâune dĂ©marche systĂ©mique. Les conclusions de lâESCo interviennent Ă©galement dans le cadre des dĂ©bats sur le champ dâapplication des mesures dâĂ©valuation de lâimpact environnemental de la dissĂ©mination volontaire des organismes gĂ©nĂ©tiquement modifiĂ©s. Ce dĂ©bat tend Ă se dĂ©placer vers une Ă©valuation environnementale de lâĂ©volution des pratiques dans les systĂšmes de culture.The Collective Scientific Expertise study (ESCo) carried out in 2010â2011 by INRA and CNRS on herbicideâtolerant plant varieties (HTV) was commissioned jointly by the French Ministries of Agriculture, the Food Industry and Forestry (MAAF) and Ecology, Sustainable Development and Energy (MEDDE) in response to initial proposals by the Permanent Technical Committee for the Breeding of Cultivated Plants (CTPS) regarding registration in the official French catalogue of sunflower and rapeseed varieties displaying tolerance to imidazolinone herbicides. The ESCo focused on the agronomic trait of herbicide tolerance (HT) in species that are normally susceptible, whatever the genetic breeding technique employed to give this trait to a variety. This ESCo was designed to evaluate the impacts in terms of agronomic factors, plant health, the environment, economic savings and societal perceptions of the dissemination of cultivated plant varieties presenting the genetic trait of herbicide tolerance. After its rapid adoption by farmers in the North American context, the technical solution offered by HTV has gradually spread to France, notably for sunflower (150,000 ha sown with HTV in 2015, or 20% of all sunflower land in France). In the case of rapeseed, because of the later market introduction of HTV, only 9000 ha out of 1.5 million were sown to HTV in 2013, and around 20,000 in 201416. Nevertheless, the growth potential is superior to that of sunflower, which presages its broader adoption (sowing intentions in 201517 estimated at 40,000 ha). Publication of the conclusions of this ESCo led to the design and implementation of an action plan, monitored by the MAAF and intended to provide a framework for the dissemination and use of these varieties in order to protect against the risks associated with systematically using the same family of herbicides on the same plot at the scale of the rotation. Indeed, although these HTV are likely to constitute an initial technical response to weeding problems, and although their cultivation is presented simply as enabling a reduction in the amounts of herbicide used, if their repeated cultivation does not take account of concomitant evolutions in weed flora, it can rapidly render this strategy ineffective and cause a resurgence of these problems, which may then be even more complex to manage. The action plan thus aims to implement measures to monitor the possible appearance of resistance among weeds, and to circulate recommendations and agricultural advice that can inform the choices and practices of farmers in the context of a systemic approach. The ESCo conclusions also contributed to debate on the scope of application of measures to evaluate the environmental impact of deliberately disseminating geneticallyâmodified organisms. This debate is now tending to shift towards an environmental evaluation of changes to cropping system management
OSCAR, a national observatory to support the deployment of new grapevine disease resistant varieties in France
National audienc
Intracellular Distribution of Manganese by the Trans-Golgi Network Transporter NRAMP2 Is Critical for Photosynthesis and Cellular Redox Homeostasis
Plants require trace levels of manganese (Mn) for survival, as it is an essential cofactor in oxygen metabolism, especially O2 production via photosynthesis and the disposal of superoxide radicals. These processes occur in specialized organelles, requiring membrane-bound intracellular transporters to partition Mn between cell compartments. We identified an Arabidopsis thaliana member of the NRAMP family of divalent metal transporters, NRAMP2, which functions in the intracellular distribution of Mn. Two knockdown alleles of NRAMP2 showed decreased activity of photosystem II and increased oxidative stress under Mn-deficient conditions, yet total Mn content remained unchanged. At the subcellular level, these phenotypes were associated with a loss of Mn content in vacuoles and chloroplasts. NRAMP2 was able to rescue the mitochondrial yeast mutant mtm1â In plants, NRAMP2 is a resident protein of the trans-Golgi network. NRAMP2 may act indirectly on downstream organelles by building up a cytosolic pool that is used to feed target compartments. Moreover, not only does the nramp2 mutant accumulate superoxide ions, but NRAMP2 can functionally replace cytosolic superoxide dismutase in yeast, indicating that the pool of Mn displaced by NRAMP2 is required for the detoxification of reactive oxygen species